100 On Meteorites. 
conversation among the people assembled at church. An emigrant 
Norwegian, on a visit home from America and about to return to 
this country, made a bargain with the poor woman on whose land 
the stone was found: he was to take it away for a mere song; and 
the Tysnæs meteorite came thus very near going to America. On 
coming home, however, the woman became uneasy at the idea of 
selling such a God-send—direct from heaven—and she returned the 
money. Shortly after, the district physician, Mr. Gjestland, heard 
of the stone, and, realizing its great scientific value, he at once took 
it into his charge. It is owing to this gentleman’s most obliging 
intervention that the stone—against a handsome remuneration, of 
course—was secured for the University of Christiania. This 
meteorite weighs about forty pounds. Several smaller fragments 
were also found. 
The phenomena mentioned above—viz. : a fire-ball rushing along 
and exploding with a thunder-like report, ‘followed by the coming 
down of the fragments—are those regularly observed accompanying 
the fall of meteorites. In some cases the velocity of the fire-ball has 
been ascertained to be sixty to seventy kilometres a second. This 
tremendous velocity accounts for the fire phenomenon, as the atmos- 
phere, not being able to escape before the missile, becomes conden- — 
sed to an enormous degree—a great quantity of heat thus being 
developed, according to the known physical laws. The meteorites, 
at one time having the temperature of space through which they — 
were rushing—a temperature far below the freezing point—will thus 
become enormously heated on the outside when entering the earth’s 
atmosphere. The pressure of the strongly-condensed atmosphere 
finally exceeding a certain limit, acts as a blasting-agency, according — 
to a commonly-accepted opinion, and the fire-ball explodes. The 
fragments are still glowing for a while after the explosion, but, % 
a rule, they have probably become cooled off when reaching 
ground. Nor is the final speed very considerable, the origi 
velocity of the fire-ball having been diminished by the resistance 
the air. 7 
When falling at full speed, the surface of the meteorites may be f 
supposed to be continually melting—nay, perhaps, evaporatmg — 
By the friction of the air, however, the molten substance is remov® — 
almost as fast as it is formed. In this way the “ fire-tail ”—whio® _ 
the observers in many cases affirm having seen—may be explain a | 
In the same manner the “smoke” is formed which, on several 0c f 
4S hay Oe 
